Valid output formats include mov-text (MP4 only) and CEA-708 (MPEG-TS and MP4,
29.97 and 30 frames per second only). CEA-708 captions are
embedded in the H.264 SEI user data of the stream.

Elastic Transcoder supports a maximum of one embedded format per output.

Sidecar: Sidecar captions are kept in a
separate metadata file from the audio and video data. Sidecar captions require
a player
that is capable of understanding the relationship between the video file and the
sidecar
file. Elastic Transcoder supports only one sidecar caption per language, to a maximum
of 20 sidecar
captions tracks per file.

Elastic Transcoder does not support OCR (Optical Character Recognition), does not
accept pictures
as a valid input for captions, and is not available for audio-only transcoding.
Elastic Transcoder does
not preserve text formatting (for example, italics)
during the transcoding process.

For information about transcoding captions when you're using the Elastic Transcoder
console, see
Output Details, Part 3, Caption Settings. For information
about transcoding captions when you're using the Elastic Transcoder API, see the
documentation about the
Create Job API action beginning with the
Captions element.